Circuit breaker



D. R. WISE June -8, 1948.

cIncUI'r BREAKER Y Filed Aug. 4', 1945` Patented June 8, 1948 UNITED STATES APATENT oFFlcE I :Mmm

Dollllll n Wilt, 800th Bend, Ind. Alllllmfloll lllll 4, 1945, Sel'lll No. 608,935

3 Claims. (Cl. 20G-88) l My invention relates to circuit breakers and has particular reference to such devices which automatically break the circuit upon the occurrence of an overload.

Important objects of the invention are to provide a circuit breaker which is small, simplified and has a low cost of production; to provide a circuit breaker having the size and appearance of the standard wall switch; to provide a circuit breaker so designed that it will llt into a standard commercial wall switch box and face plate; to provide a circuit breaker which'is interchangeable with a standard commercial wall switch and can be substituted therefor; to provide a circuit breaker of such simplied construction that only one pin, rivet or screw is used in the complete assemblage for holding the main parts together; to provide a circuit breaker wherein the automatic-circuit breaking device is trip free from the handle; tok provide a circuit breaker wherein the automatic circuit breaking device is released by the action of a thermostatic element under light overloading conditions, and on heavier overload kconditions or short circuits by an electromagnet; to provide a circuit breaker in which, under normal operating conditions with no overload or short circuit. the circuit breaker is operated as a manually operated switch; and to provide a circuit breaker wherein the contact or breaking operation is quick, upon either manual or automatic operation.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this application and in which like numerals are used to designate like parts throughout the same.

Figure 1 is a perspective view of a circuit breaker or switch embodying my invention,

Figure 2 is a transverse section taken on line 2-2 of Figure 5.

Figure 3 is a central longitudinal section taken on line 3-3 of Figure 2, with the operating Y handle in the Oli position,

Figure 4 is a similar view with the operating handle in the n" position,

Figure 5 is a similar view of the operating handle in the neutral position and the circuit opened,

Figure 6 is a horizontal section taken on line 6 0 or Figure 3, and

Figure 7 is a perspective view of the trip lever and associated elements.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral yIII designates a casing as a whole, which is formed of suitable insulating material, such as Bakelite This casing includes ends II, a top I2 and bottom I3. 'I'he top is provided with an elongated opening I4, having parallel side walls I5 and circularly curved end walls I6. The circularly curved end walls I B are concentric with each other and with pivots Il. to be further described. The casing I0 further comprises sides Il and I3'. The casing I0 is vertically split at I9', forming a major casing section 29', and a minor casing section or cover 2l', held together by a single pivot element or pin I9. the ends of which may be spread, or this pin may have screw threaded engagement with the sides I8 and Il', or attached thereto by any suitable means. The side I8 has projections or places I9` to enter the major cas-ing section 20.

The major casing section 20' is provided upon the inner face of one end l i with a recess 20, for receiving a stationary contact 2l, having a contact part or point 22. The stationary contact is held in place by a binding screw 23, having screw threaded engagement therewith, and this binding screw extends to the exterior of the casing for connection with a wire 24. The opposite end II oi the major casing section 20' has a recess 25, for receiving the lower end of Y a bi-meta'l thermostatic element 26. This lower end has a screw threaded opening 21 for receiv-` ing a binding screw 28, extending to the exterior of the casing for engagement with a wire 29. 'I'he bi-metal thermostatic element has an in- I ing suitable slack.

The numeral 3l designates a movable or swinging contact, the upper end of which is equipped with an apertured knuckle 38, pivotally mounted upon the pin I9. This apertured knuckle has an upstanding crank 39, formed integral therewith, and this crank is provided at its upper end with a. ball 40. 'I'he crank 39 is slightly inclined with respect to the movable contact. The movable contact 31 is provided near its lower end with a contact part or point, arranged to engage and disengage the stationary contact part 22, as shown. A Iwire 42, having sumcient slack, is electrically connected with the movable contact I1 andwith one end of the winding ll.

The numeral It designates a trip-lever, including a bottom M and sides Il. The sides are provided with upwardly projecting dogs or extensions II. The sides 4I are provided at their ends with spaced apertured knuckles l1, arranged upon the opposite sides oi the knuckle Il, and pivoted upon the pin it. The trip-lever Il tapers toward its end remote from the pin il and its bottom is inclined or rounded adjacent to its tapered end, as shown at 41, for coaction with the upper inclined face ll of the latch-head Il. Ine bottom u of the triplever is provided with a boss or stud Il, extending into the upper end of a. compressible coil spring vIl, the lower end of which receives a boss or stud Il, carried by a stationary lug I2, formed integral with the bottom I8 ot the maior casing section 2l'. It might be stated at this point that thefree end of the trip lever Il may engage beneath and be held by the latch-head Il, in opposition to the spring It. When the thermostatic element 2t is heated, due an overload, its upper end moves laterally from the free end of the trip-lever I8, whereby the trip lever is released by the latch-head ti and the spring Il will then swing the trip-lever upwardly.

The numeral 5l designates an operating lever, having a base il. This operating lever is mounted within the opening Il and has ilat parallel sides II to slidably engage the sides l5 and circularly curved end sides Il, to slidably engage the end walls il. The base ll carries the pivots I1. preferably formed integral therewith. The circularly curved ends It are concentric with the pivots I1 andwith the end walls Il, as shown. The top i2 of the casing sections 2l and 2| is provided with openings l1, for pivotally receiving the pivots i1. The base I4 has a shoulder il' to engage the trip-lever 43 and reset it.' The base I4 has). recess II receiving a compressible coil spring Il, the upper end of which receives a ball Il. formed integral with the operating lever, as shown. The lower end of the spring il receives the ball ll. The spring Il is stiffer or stronger than the spring 5l and can overcome the action of the spring Il.

The operation of the switch is as follows:

In the absence of .a light overload or heavy overload or short circuit, the circuit breaker is used as an ordinary wall switch. When the operating lever Il is swung to the right sumciently so that the ball ti moves beyond the dead center of ball It, the spring l! quickly swings the movable contact l1 to the on position, contact parts 22 and 4i engaging, Figure 4. When the operating switch ll is swung to the left until the ball Il passes the dead center of the ball Il when the movable contact is in the on" position, then the spring 5l quickly swings the contact l! to the olf position, Figure 3. During these operations, the trip-lever is held in the retracted position by engaging behind the latch-head Ii. When the swinging contact 31 is in the on position, Figure 4, and a light overload occurs, the increased current passing through the bi-metal thermostatic element il heats this element and the thermostatic element moves the latch-head Il out or engagement with the trip-lever 4I', and spring Il swings the trip-lever toward the crank Il. The dogs 4I now engage crank Il and overcoming `the action of the spring It, since spring 4 Il is stronger than spring it, Il to the position. now assumes an intermediate To reset the trip-lever 4I, the isswungtotbelefttotheextremeol! andtheshoulder N'willdepreasthetriplever and restore it to its position beneath the latchhead, the thermostatic element having now cooled and returned to its normal position. 'nils restoring of the trip-lever in no way moves the swinging contactll. When the contact I1 is in the Ion position, Figure 4, and a high overload or short circuit occurs. the electromagnet Il is quickly energised before the thermostatic element It has had time to suiiiciently heat for functioning. and this electromagnet draws the free end of the thermostatic element from the trip-lever It. whereby the latch head Il releases the trip-lever. This trip-lever then operates to swing the contact 81 to the oi!" position. The trip-lever is reset in the manner stated. The bi-metal thermostatic lelement It is formed of two metals one of which would be iron so that it is attracted by the electromagnet. The element Il is suiliciently resilient vto return to its normal position when released by the magnet.

Itlstobeunderstoodthatthe formofmyinvention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape. sise, and arrangement'of parts may be resorted to without departing from the spirit of my invention or the scope of the subloined claims. i

Having thus described my invention. what I claim is:

l. A circuit breaker. comprising a support, an operating lever pivotally mounted upon the support, a main pivot mounted upon the support and separate from and in substantial alignment with the pivot of the operating lever, a swinging lever pivotally mounted between its ends upon the main pivot and including a crank disposed upon the same side of the main pivot with the operating lever, the crank being shifted to positions upon opposite sides of the pivot of the operating lever lwhen the swinging lever is moved upon its pivot, a compression spring extending substantially aliallv of the operating lever and having one end secured to the operating lever and its opposite end secured to the end of the crank, a trip lever mounted upon the mainpivot and having a part to contact with the crank when the trip lever is swung toward the crank and operating lever, a compression spring engaging the trip lever and arranged upon that side thereof remote from the first named compression spring, circuit closing means operated by the swinging lever, and releasable latch. means to engage the trip lever, the arrangement being such that the trip lever when 'released is shifted toward the operating lever and crank to move the crank. L

2. A circuit breaker, comprising a support, an operating lever pivotally mounted upon the support and including a base provided with a recess extending axially of the operating lever, a main pivot separate from the pivot of the operating lever and mounted upon the support. a swinging i lever pivotally mounted lbetween its ends upon the main pivot and including a crank disposed upon the same side of the main pivot with the base, the crank being shiftable to positions upon opposite sides of the pivot of the operating lever, a compression coil spring extending axially withintherecessandhavingoneendsecuredtothe operating leverandits oppositeendseouredto the end of the crank, a trip lever mounted upon the main pivot and having a lateral extension projecting toward the operating lever and crank to engage the crank and move it, a compression coil spring engaging the trip lever and arranged upon that side of the trip lever remote from the lateral extension, a releasable latch device to engage the trip lever, and circuit closing means operated by the swinging lever.

3. A circuit breaker, comprising a support, an l0 operating lever pivotally mounted upon the support and including a base provided with a recess extending axially of the operating lever, the operating lever being provided with an internal head at the closed end of the recess, a main pivot mounted upon the support and spaced from the pivot of the operating lever and in substantial alignment therewith, a swinging lever pivotally mounted between its ends upon the main pivot and including an arm and a crank, the crank being angularly disposed with respect to the arm and arranged upon that side of the main pivot next to the base and having a head at the free end of the crank, a compression coil spring extending axially within the recess and receiving the heads in its opposite ends, a trip lever mounted upon the main pivot and having a lateral extension projecting toward the operating lever and crank to engage the crank when the trip g sion coil spring, a releasable latch device i'orco-action with the trip lever, and means to limit the movement of the swinging lever in opposite directions including a circuit closing device.

DONALD R.. WISE.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,809,275 Jennings June 9, 1931 2,026,373 Bush Dec. 31, 1935 2,160,424 Taylor May 30, 1939 2,182,864 Frank Dec. 12, 1939 2,190,517 Jennings Feb. 13. 1940 2,214,695 Jennings Sept. 10, 1940 2,325,717 Swingle Aug. 3, 1943 2,331,012 Woods Oct. 5, 1943 25 2,360,684 Jennings Oct. 17, 1944 FOREIGN PATENTS Number Country Date 13,590 Great Britain July l, 1905 

